1. Field of the Invention
The present invention relates to a slide valve apparatus and a method of manufacturing the slide valve apparatus, particularly, to a slide valve apparatus used in a micro chip for performing the reaction and the analytical chemistry and to a method of manufacturing the same.
2. Description of the Related Art
In recent years, it attracts attentions to carry out a chemical reaction in a micro space in a micro chip partly because it is possible to decrease markedly the amounts of the sample and the reagent used in the analysis of, for example, the health and the environment and partly because it is possible to increase the reaction rate. Also, it is desirable to mount a valve to a micro chip in order to further improve the reaction and the analysis.
Several methods have been proposed to date in respect of the mounting of a valve to a micro chip including the method of deforming a membrane so as to close the fine fluid channel within the micro chip. For example, known is “Monolithic membrane valve and diaphragm pump for practical large-scale integration into glass microfluidic devices” by Grover, W. H. et al, Sens. Actuators, B2003, 89, pp. 315-323. In the membrane system, a membrane made of a soft material having a high resistance to chemicals such as PDMS is pushed against a fine fluid channel by utilizing, for example, air pressure so as to allow the membrane to close the fine fluid channel, thereby controlling the flow of the fluid in a manner to block the flow of the fluid within the fine fluid channel.
A slide gate system has also been developed as a method of mounting a valve to a micro chip, for example, “Low-Leakage Micro Gate Valve” by Albert P. Pisano, et al, Transducers '03, Berkley USA, Jun. 11, 2003, pp. 143-146. In the slide gate system, a member used as a gate is inserted into a fine fluid channel so as to control the fine fluid channel in a manner to block the flow of the fluid within the fine fluid channel.
However, in the valve of the membrane system, the membrane is deformed so as to make it necessary to mount a membrane and provide a space for allowing a deformation of the membrane in the vicinity of the fine fluid channel. It follows that, in the valve of the membrane system, an unduly broad portion in view of the flow of the fluid, which is herein called a dead volume, is generated in the fine fluid channel. Generation of the dead volume brings about a difficulty in the case where different kinds of fluids are consecutively allowed to flow alternately within the fine fluid channel. To be more specific, different kinds of fluids are mixed in the dead volume before the fluid staying in the dead volume is replaced by another fluid that is newly allowed to flow through the fine fluid channel so as to cause the contamination. It should also be noted that when the membrane is deformed so as to close the fine fluid channel, the liquid within the fine fluid channel is caused to flow out of the fine fluid channel. Alternatively, when the membrane is deformed so as to open the fine fluid channel, it is possible for the flow within the fine fluid channel to be pulled backward so as to make it difficult to control the flow within the fine fluid channel.
On the other hand, in the valve of the slide gate system, a clearance is formed in the slide portion of the gate. Since the fluid enters the clearance, it is possible to bring about the contamination in the case of allowing different kinds of liquid materials to flow through the fine fluid channel.